The proposed research aims at understanding the catalytic mechanism and inhibition of human erythrocyte carbonic anhydrase at the molecular level. Experimental approaches include enzyme kinetics, chemical modification of active site group, inhibitor binding, and magnetic resonance and spectroscopic investigations. Methods for the efficient and rapid isolation of the native and chemically modified carbonic anhydrases are also explored using affinity chromatography techniques. BIBLIOGRAPHIC REFERENCES: Khalifah, R.G., and Strader, D.J. (1977) "A 13C nuclear magnetic resonance approach to enzyme active sites. Carbonic anhydrase," Proc. Second Maine Biomed. Sci. Symp., in press. Khalifah, R.G. (1977) "Histidine 200 alters inhibitor binding in human carbonic anhydrase B. A 13C nuclear resonance identification," Biochemistry, in press.